The present invention is generally directed to a system for providing optical fiber connections to multi-chip electronic circuit modules. More particularly, the present invention is directed to a connector and a module/connector combination which is capable of providing optical fiber connections to chips on a multi-chip module through the utilization of standardly available fiber optic cable connectors. Even more particularly, the present invention is directed to a mechanism for providing plugable connections between exterior fiber optic cable packages and electronic circuit chips disposed on an interior substrate. These chips include communication means for generating and/or receiving optical fiber transmission signals. The problems associated with connecting fiber optic cable bundles and ribbon packages to multi-chip circuit modules are discussed in U.S. Pat. No. 5,337,388 issued Aug. 9, 1994 and also in U.S. Pat. No. 5,333,225 issued Jul. 26, 1994. Both of these patents are assigned to the same assignee as the present application.
The problems encountered in trying to establish the above described opto-electronic connections are generally severest with respect to the problem of aligning hair-thin fiber optic cables with corresponding cables in the connector, and with providing connections from the connector to individual circuit chips. The problem of alignment is exacerbated by changes in dimensioning produced by thermal effects. These thermal effects arise from the heat that is generated within the electronic circuit chip components. The thermal problems are worsened by operation of these circuit chips at high frequencies, which are necessary to provide fast circuit operation but which generate large amounts of heat. This is particularly true in electronic components that are part of computer systems.
In addition to the problems associated with thermal expansion, another problem encountered in attempting to provide a suitable connector is the problem of electrical isolation. Because electrostatic charges can accumulate on fiber optic cables and on other associated plastic and insulative components, it is very desirable to provide a mechanism by which such static discharges may be dissipated without causing injury to electronic circuit components which can be particularly sensitive to static discharge.
Additionally, it is noted that a connector which mates optical fiber cables to the interior of multi-chip modules should also provide a mechanism for environmental isolation of the circuit chips from the exterior environment. In particular, it is typically desirable to operate a multi-chip module (MCM) in a variety of atmospheric conditions which may include above average levels of relative humidity, dust and/or particulate contamination. These atmospheric contaminants should in general be unable to penetrate a seal designed to enclose a multi-chip module. Furthermore, the connector should be compatible with sealing and cooling arrangements which permit chip cooling mechanisms to be employed.
In short, it is seen that a cable connector for the present purposes should be compatible with chip protection from contamination while nonetheless being immune from thermal expansion effects and yet providing electrostatic isolation for circuit chips inside the module.